South Africa's Supreme Court of Appeal is expected to rule on Wednesday on South Africa's obligation under international law to probe alleged atrocities by officials in Zimbabwe.
"This case is the first of its kind to be brought before the South African courts and will set an important precedent," Southern Africa Litigation Centre deputy director Priti Patel said in a statement on Tuesday.
"The judgment will provide content to the obligations South Africa assumed under international and domestic law to ensure that the world's worst criminals are held accountable for their actions."
On November 1, a full Bench heard there was no suggestion from any party that the South Africa Police Service (SAPS) should investigate alleged crimes against humanity on Zimbabwean soil.
"Do an investigation here," Advocate Wim Trengove, for the centre, said at the time.
The court was hearing argument in an appeal against a decision that South Africa was obliged under international law to probe alleged atrocities by officials in Zimbabwe.
The lower court held that the National Prosecuting Authority could prosecute the Zimbabweans concerned if they ever set foot in South Africa.
Zimbabwean officials are accused of masterminding crimes against humanity by instituting a state-sanctioned reign of terror in their own country.
Trengove said that even if it was later found the victims might have lied, the police could not refuse an investigation, "but they [the police] must investigate first".
Trengove said there would be no need to go on if the investigation proved to be futile.
"Until they exclude the prospects that these people would not come to South Africa, they cannot stop investigating the matter."
He said the contention that a crime became a crime only when the perpetrator entered South Africa was wrong.
Earlier, police spokesperson Andre Ferreira , said they could investigate a person allegedly involved in a crime only when that person set foot in the country.
He argued that to spend resources on an investigation where there were no prospects of a prosecution, such as if a foreigner might enter the country, would be wrong because it would lead to nothing.
He contended that only strict presence in South Africa was the trigger for an investigation and not an anticipated presence, as argued by the opposing side.
The original court action was brought by the centre and the Zimbabwean Exiles Forum.
They asked the high court to review and set aside a decision by the National Director of Public Prosecutions and the police not to investigate Zimbabwean officials allegedly linked to torture.
The high court found in their favour and the police appealed to the appeal court. – Sapa